脑梗死前期MR脑灌注成像的临床意义

目的 探讨脑梗死前期MR脑灌注成像的表现和分期临床应用价值。方法 采用脑MR灌注成像对18例脑血管病患者的170层脑灌注图像和对照组20例非脑血管病患者的197层脑灌注成像进行分析，计算每层图像的患／健侧比值，并与对照组的正常比值及其范围比较。以非参数统计方法、多元方差分析和两两比较分析病例组和对照组脑灌注血流动力学参数及其分期。结果 病例组和对照组的4个血流动力学参数均有显著性差异（P〈O.01）。TTP（time to peak）和MTT可（mean traasit time）与发病的相关系数较高，分别为O.422和0.371，rCBV（regional cerebral blood volume）和rCBF（regional cerebral blood flow）较低，且为负值。脑梗死前期分期特征为：I1期TTP稍有延长，I2期MTT显著延长，Ⅱ1期rCBF明显下降，Ⅱ2期rCBV下降。结论 脑灌注成像可提供脑梗死前期的血流动力学参数变化的信息，并可以对其参数变化进行分期。

Correlation analysis of magnetic resonance perfusion imaging and its stages of regional cerebral hypoperfusion in pre-infarction period

Objective To explore clinical value of application to magnetic resonance(MR) perfusion imaging and stages of regional cerebral hypoperfusion in pre-infarction period and improve the diagnosis level for pre-infarction period,and prevent or decrease the incidence of cerebral infarction.Methods 18 cases of cerebral ischemia in case group and 20 cases of non-cerebral ischemia in control group were performed with dynamic perfusion MR.170 MR images of case group were compared with 197 images of control group,calculating the ratios of illness side to normal for every image at hypoperfusion areas in the regional cerebral ischemia and referring and comparing their range provided by control group with methods of nonparametric statistics and multivariate analysis of variance and multiple comparison.Results Four parameters of blood flow dynamics between two groups showed a significant difference(P<0.01).Correlation coefficients between time to peak(TTP) and time to peak(MTT) and incidence of regional cereberal hypoperfusion in pre-infarction period were higher,0.422 and 0.371 respectively,but regional cerebral blood volume(rCBV) and regional cerebral blood flow (CBF) were lower,and also negative.The characters of stages of regional cerebral hypoperfusion in pre-infarction period were as follows: Stage I_1,TTP delayed slightly;stage I_2,MTT extended markedly;stage II_1,rCBF dropped significantly;stage II_2,rCBV decreased.Conclusions The information of regional cerebral hypoperfusion in pre-infarction period might be provided by MR cerebral perfusion and stages of pre-infarction period could be designated with the change of blood flow dynamics parameters.